Signal station



H. E. SEATON SIGNAL STATION May 11, 1965 5 Sheets-Sheet 1 Filed April 9, 1963 H. E. SEATON S IGNAL STATION May 1l, 1965 Filed April 9, 1963 3 Sheets-Sheet 2 H. E` SEATON May l1, 1965 SIGNAL STATION 5 Sheets-Sheet 3 Filed April 9, 1963 v INVENTOR. garda/75mm BY/Zown ,MAW

United States Patent O 3,183,501 SIGNAL STATION Harold E.. Seaton, Shelby, Unio, assigner to rihre Autocall Company, Shelby, hio, a corporation oi @hie Filed Apr. 9, 1963, Ser. No, 271,653 l2 Claims. ('Cl. 34e- 296) The present invention relates to signal stations, adapted primarily for signalling emergency alarms. These emergency alarms are typically represented by re alarms, evacuation alarms, shelter alarms, and the like; but, as will hereinafter appear, my improved signal station is not essentially limited in its use to the transmission of emergency alarms, but it may also be used as an authorized employee call transmitting station, such as a watchmans call box or the like.

The first mentioned group, including lire alarms, evacuation alarms and shelter alarms, are conventional and well known. With regard to the second mentioned group, including authorized employces call stations, etc., one illustrative installation might be in an industrial plant in which a foreman supervises a substantial area of machines or processes where emergency conditions might arise. Upon an emergency condition arising at a particular machine or process, the operator of that machine or process would promptly actuate the nearest signalling station into the rst position or first stage of its operation, thereby lighting call lights, and possibly sounding an audible signal, in that particular area and in the oremans oiiice. The oreman would immediately investigate the emergency, and if additional help were needed, he would actuate the signalling station into its second position or second stage of signalling operation, thereby either sounding a general alarm, or calling in a specialist versed in the problems of the machines or process in that area, such as electrical problems, chemical problems, hydraulic problems, etc.

One of the objects of the invention is to provide an improved signal station having a multiple position or multiple stage type of operation. in the first position or preliminary stage of operation, the signal station transmits what might be termed a pre-alarm signal, such being performed through the operation of a tirst electric switch. This first stage of operation can be effected by any workman or any other person in the immediate vicinity of the signal station. ln the second stage of operation, the signal station transmits an emergency or fullalarm signal through the operation of a second electric switch. The construction of the signal station is preferably such that this second stage of operation can only be performed by an authorized person having an authorized key or other authorizing instrumentality.

Another object ot the invention is to provide a signal station of the above general description, in which the signalling operations are manually performed by a person pulling down a so-called pull-down slide mounted at the front of the signal station. rlhe signal box is caused to operate into its two stages or two positions by two successive downward pulls of the pulldown slide.

Another object of the invention is to provide improved key-released latch mechanism for controlling certain movements of the slide panel. For example, the provision of this latch mechanism prevents the slide panel from being pulled down into the second position or second stage of operation for signalling a general alarm, except by an authorized person having an authorized key for releasing the latch mechanism. Furthermore, the release of the latch mechanism by an authorized key is required in order to restore the slide panel from its second position or second stage of operation back into normal position; or in order to move the slide panel upwardly into a position Patented May 11, 1965 ICC which will permit the replacement of a frangible insert with which the signal station is provided.

Another object of the invention is to provide the signal station with an improved arrangement for mounting and fracturing a frangible insert, which is adapted to be broken by the initial pull-down movement of the slide panel from its normal position into its iirst signalling position. By virtue of the improved construction and operation of the rangible insert mounting means and fracturing means, this frangible insert may be in the form of a conventional or staple type of commodity of relatively inexpensive construction. For example, it may consist of a short length of tubing or slender rod composed of liber, glass, or other readily fracturable material, which is merely dropped into place in a receiving socket in the signal station. Thus, the delay and expense of replacing a glass window of predetermined size is avoided.

Another object of the invention is to provide improved mounting arrangements for mounting the electrical switches in the signal station. In one embodiment of the invention, l contemplate using conventional electric switches of the type operated by toggle levers movable back and forth in a single operating plane. When using such switches, the signal station is provided with improved switch mounting means which insures that the electrical switches will be mounted in correct positions and will remain in these correct positions, with the single operating plane of each electrical switch disposed at the proper angle for actuation of the toggle levers by deiiecting surfaces moving with the slide panel.

Other objects, features, and advantages of the invention will be apparent from the following detailed description of one preferred embodiment thereof.

ln the accompanying drawings illustrating such embodiment:

FIGURE l is a front elevational view of the signal box, with the front slide panel in its normal upper position;

FIGURE 2 is a vertical transverse sectional view taken approximately on the plane of the line 2 2 of FIG- URE l;

FIGURES 3 and 4 are horizontal transverse sectional views taken on the plane of the line 3 3 of FIGURE 6, and on the plane of the line 4 4 of FIGURE l, respectively;

FIGURE 5 is a fragmentary front view broken away to show more of the rear housing or box which serves to mount the operating parts of the signalling station;

FlGURE 6 is a view of the front portion broken away to illustrate the positions of the electrical switches, rotatable latch, and trangible insert when the slide panel is in its normal raised position, as shown in FIGURE l;

FIGURE 7 is a view similar to FIGURE 6 but showing the different positions of the above parts when the slide panel is being pulled down into its irst signalling position or operating stage;

FIGURE 8 is a view similar to FIGURES 6 and 7, but showing the positions of the two electrical switches and of the rotatable latch when the slide panel has been moved down into its second signalling position or second operating stage;

FIGURE 9 is a sectional view showing the rotary latch and locking lugs in the same relation as illustrated in the right-hand lower portion of FIGURE 6, but on a larger scale;

FIGURE l0 is a vertical transverse sectional view taken approximately on the planes of the lines itl 1tl of FIGURES 6 and 9;

FlGURE ll is a detail sectional View, showing the key receiving end of the latch, taken on the plane of the line M ll. of FIGURE 9;

FIGURE 12 is a similar sectional view of the latching ward, taken on the plane of the line 12-12 of FI"- URE 9;

FIGURE 13 is a diagrammatic sectional view taken approximately on the planes of the lines 13a-i3 of FIG- URES 9 and 10, but showing the latch nose riding on the cam lobe 92;

FEGURE 14 z's a vertical transverse sectional view through the embodiment having a switch connecting terminal block for connecting with the plurality of electrical switches;

FGURE 15 is a rear elevational view of the switch connecting terminal block;

FIGURE 16 is a vertical .sectional view taken on the plane of the line 1.616 of FIGURE 14;

FIGURE 17 is an elevational view of the locking ring or washer used in the modified embodiment which dispenses with the terminal block;

FIGURE 18 is a transverse sectional view taken on the plane of the line 18-18 of FIGURE 17; and

FIGURE 19 is a transverse sectional view showing the interlocking relation established by the locking ring between each of the electrical switches and the cover plate.

In its preferred embodiment, the alarm apparatus is mounted on a stationary metallic housing 20 of box-like form adapted to have support upon any suitable supporting wall, post, or other surface where it will be readily visible for emergency use. This housing 20 comprises a back wall 21, side walls 22., 22, and top and bottom walls 23 and 2d, all preferably joined together as an integral die casting; or the box may be punched out of sheet metal. Provided in the back wall 21 are holes 2d for receiving screws or bolts for mounting the box on the supporting surface; and provided in the top and bottom walls 23 and 2dare knock-out plugs or openings 28 for permitting the entrance of an electrical conduit to establish electrical connections with the switches ot the device. Formed integral with the top and bottom walls 23 and 24 are inwardly disposed threaded bosses Sti for receiving front fastening screws 32; and, as best shown in FIGURE 5, the top wall 2.3 is also formed with a raised central portion 34.

Secured over the open front of the stationary box housing Zt is a stationary die-cast cover plate 55 having holes 3d therein through which pass the above fastening screws 32 which thread into the bosses 3S and rigidly secure the cover plate over the housing. This cover plate 3S has the same outline or perimeter as the rear housing 2G, and projecting rearwardly from this cover plate 35 around its entire perimetrical edge is a small closure bead 37 which has tight fitting abutment against the forward edges of the box Walls 22, 23, 2d and 34.

The cover plate 3S comprises a back wall 38, trom the right and left hand edges of which extend two forwardly projecting flanges or side lips 39, 35? that function as contining side guides for the vertically movable slide panel d0, which will be later described in detail. Mounted centrally of the bach wall 33 of the cover plate are two electrical switches dit, 44', which are preferably ot the conventional nger operated toggle type, each cornprising a forwardly projecting linger lever 45, d5 having a ball end. The electrical contacts of each switch are enclosed in a rectangular switch housing 4d composed of insulating material, from the front side of which projects a tubular stem d8 in the front end of which the actuating lever 45 is mounted for snap actuation. The two switches are so mounted on the cover plate 35 that the two actuating levers d5, di throw their respective switching contacts from normal non-signalling positions into abnormal or actuated signalling positions as these levers are pushed or deflected sidewise from. the right-hand positions shown in FIGURE 6 into the lett-hand positions shown in FGURE 8. When the signal station is used with normally open circuit signalling systems the switches ,les

,tot

dd, de normally stand in open circuit positions, and when used with normally closed circuit signalling systems these switches normally stand in closed circuit positions. In the present embodiment ot the invention shown in FIGURES 1-16, the switches 4d, dd are mounted on the bach side of the cover plate 3S in a U-shaped stamping S1 comprising a vertically extending bridge portion .'32 from the ends of which are bent rearwardly extending legs 53, 53'. Punched out in the bridge portion 552 are circular holes .'55, 55' through which extend the forwardly projecting threaded stems d8 of each electrical switch. The two circular holes 55 have matching alignment with two circular holes 55, Se provided in circular depressions 57, S7 formed in the back wall 3S ot the cover plate 35'. The threaded stems t8 of the two switches extend through these pairs ot aligned holes 55 and 5d, and receive nuts S9 over their front ends for rigidly securing the switches and the switch mounting clip or stamping S11 to the back side of the die-cast cover plate 3S.

Referring more particularly to the switch mounting clip or stamping 5I, it will be seen from FIGURE 15 that the vertical bridge portion 52 thereof has two lugs 62, 62 punched out to project rearwardly from this bridge portion into the space between the adjacent sides or the two switch housings d6, 46'. These lugs insure that in the assembly and mounting of the Switches it is essential that the switch housings 4s, extend horizontally crosswise of the switch mounting clip and of the cover plate 3b' so that the toggle snap levers 4S, d5 will always operate horizontally between lett and right hand positions. The switch mounting clip 51 is also held against any sidewise swivelling movement on the back side ot the cover plate 35 by the formation of two laterally spaced confining lugs d4 projecting rearwardly from the cover plate in position to engage the side edges of the vertical bridge portion S2. The opposite vertical edges of the bridge portion d2 are provided with forwardly bent side lips or flanges GS which embrace the sides of the depressions 5'7 extending rearwardly from the cover plate, thereby insuring tlat anchorage of the bridge portion against the back side of the cover plate.

The upper and lower legs 53 of the switch mounting clip 51 have mounted on their rear ends a terminal block 7) composed of insulating material. Extending in prolongation of each of the legs 53 is a pair of tongues '71 having outwardly bent confining lips 72 at their rear ends. These tongues 71 and lips 72 are passed outwardly through holes 73 in the end portions of the terminal `block 70, with the legs 53 squeezed inwardly slightly, following which the resiliency of the legs 53 causes the lips 72 to snap outwardly over the back side of the terminal block `for securely mounting the block to the legs. Extending crosswise or the rear side or the terminal block and anchored between raised insulating partitions '76 are rnetallic terminal clips 77, which have electrical connection with the contacts in the switch housings d6 through conductors 73, and which are also adapted to have electrical connection with the external conductors of the alarm circuits through terminal screws 79.

Referring again to the `front side of the stationary cover plate 35, it will be seen from FIGURES 3 and 6 that the side anges 39 which laterally contine the vertical pulldown motion ofthe front slide panel 4G, are each provided with pairs ot upper and lower guide lugs SZ projecting inwardly from the guide flanges 39 in a plane spaced forwardly from the back wall 36. These guide lugs S2. engage side guide grooves 83 in the slide panel itl for preventing the slide panel from falling forwardly away from the stationary cover plate 35, as will be presently described.

`Projecting `forwardly from the back `wall 3S at the bottom of the cover plate 35 is an integrally formed mounting socltet @e for mounting a trangible breakage insert which is adapted to be fractured when the front sliding panel is pulled down in the first-stage operation of 5. transmitting a local or prealarm signal. This frangible breakage insert is preferably in the form of a short cylindrical rod or tube S composed of glass, fiber, or other readily fracturable material. The socket 34 is formed with two forwardly projecting fingers S6 having upwardly curved front ends, these fingers being operative to support the fracturable insert only at the ends thereof, so that an adequate downward pressure applied to the intermediate portion of the insert can break it downwardly into two or more pieces for dropping down through the open clearance space between the fingers 536. The socket 84 also has forwardly projecting end flanges 8'7 disposed beyond the fingers 86, and a top flange 88 disposed above the lingers, this top liange having an entrance opening 39 therein, through which a fracturing wedge or ram 90, carried by the slide panel 4), moves downwardly to fracture the insert when the slide panel is pulled down through its tirst stage of signalling operation.

Also formed integral with and projecting forwardly from the cover plate 35, above the insert socket 84, is a vertically aligned series of three stationary stop cam lobes 91, 92, and 93, which are successively followed by stationary latching notches g4, 95, .and 96. These latching cam lobes and notches cooperate with a reciprocable, rotatable latch 10d carried on the back side of the reciprocable slide panel 4?. rThis slide panel 45, also preferably constructed in the form of a die casting, comprises a front wall 98 having side guide flanges 99, 99 projecting rearwardly therefrom and spaced slightly inwardly from the side edges yof the panel to have free sliding movement between the forwardly projecting guide lips 39 of the cover plate 35. The guide grooves 83 which slidably engage over the guide lugs 82 are formed on the outer sides of the ranges 99, 99'. rlVhe upper portion of the slide panel 40 is formed with a rearwardly recessed finger pocket 11M of rectangular form, int-o which the operators iingers are inserted for pulling down the slide panel 4@ in the performance of the iirst stage of alarm signalling. A downwardly pointing arrow 1125 on the back wall of the ringer pocket denotes that the slide panel is to be pulled downwardly, and this may also be indicated by an instructing legend 165 on the slide panel below the linger pocket. A small horizontal sight window 108 is provided in the slide panel adjacent to its bottom edge which, in the normal upper position of the panel, indicates whether or not a fracturable insert 85 is in its normal position in the socket 84. As will be hereinafter described, the mounting of the fracturable insert'S, or the provision of the socket 84 for receiving the same, are optional requirements depending upon state laws, ordinances or customs at the place of installation.

Referring now to the back side of the slide panel 4i?, as shown in FIGURE 6, it will Ibe seen that the wedge or ram 90 which fractures the insert 85 continues upwardly as a rearwardly projecting rib formed integral with the slide panel 40 and having its upper end inclined laterally to form a switch detiecting wing 111. Spaced laterally from this wing 111 is a correspondingly deflected companion wing 111', this latter lwing continuing upwardly as a vertical rib 115 disposed approximately in prolongation of the fracturing rib 90. The spaced deilecting wings 111 and 111 define an inclined cam slot 110 therebetween, which operates lirst on the switch actuating toggle lever 45 in the iirst stage lof operation, and then operates on the second switch operating toggle lever 45 in the second stage of downward sliding movementof the slide panel 4t), as will be later described in connection with FIGURES 7 and 8. The lower end of the fracturing rib 9i) is formed with a blocking offset 90 (FIGURES 68), the purpose of which will be described later.

Mounted vertically along the inner surface of guide flange 99 of slide panel 4@ is the rotatable latch 105i which cooperates with the three stop cam lobes 91, 92, and 93. This latch comprises a long cylindrical shank ltitlcz which has rotative mounting in upper and lower semi- 6. cylindrical bearing seats 114, formed integral with and projecting rearwardly from the back of the slide panel. In the mounting of the latch, the shank 10de can be readily inserted sidewise or diagonally downwardly into these semi-cylindrical bearing seats 114, 115, the latch being releasably retained therein by the proximity of the back wall 38 of cover plate 35 when the slide panel 46 is slid down over the front of the cover plate 35. An upper head or hub portion 10011 at the top of the latch shank ltita has a latching nose or pawl 100e projecting therefrom for cooperating with the stop cam lobes 91, 92, and 93. When the shank portion 1tl0a has been inserted into the semi-cylindrical bearing seats 114, 11S, the rotatable latch is held against relative upward sliding movement within these bearing seats by an abutment lug 117 projecting rearwardly from the slide panel 411 in position to engage the top of the upper head portion 1665, and is held against relative downward sliding movement within said bearing seats by the abutment of the bottom end of the shank portion against a bottom wall 1351 of the slide panel 40.

A torsion spring 12@ acts continuously on the latch 10i? tending to revolve it in a clockwise direction as viewed looking downwardly in FIGURE 4, so as to hold the latch nose 100C resiliently pressed rearwardly against the stop cam lobes 91, 92, and 93. This torsion spring is preferably in the form of a flat reed spring having its lower end entering a slot wild extending down into the top of the lupper head portion ltllb of the latch. The upper end of this torsion spring is pressed into a narrow anchoring slot 122 delined between the side guide lange 99 of the slide panel and the end wall of the linger pocket 1&4.

The latch 1th) is adapted to be rotated counterclockwise (FIGURE 4) to a releasing position, in opposition to the normal torsional bias exerted by the spring 123, through the rotation of a releasing key 125 which is adapted to be inserted into the lower end of the latch shank ttla. This lower end of the latch shank rests against the bottom wall 131 which projects rearwardly from the slide panel in position to close off the bottom of the lower bearing seat 115. Extending upwardly into the lower end of the latch shank little is a key socket 127 of special configuration for receiving the key 125. In the exemplary form shown, the major portion of this key socket has a circular outline 127e, but extending outwardly therefrom are two grooves or channels 1271:, 127!) spaced about 90 apart. Extending through the bottom wall 131 in alignment with the key socket 127 is a ward opening 128 which has a matching circular portion 128a and outwardly radiating grooves or channels 128b, 128b, corresponding to the shape of the key socket 127. The key 125 has a cylindrical shank 125er from which project two lengthwise key ribs 125b, 125b also spaced approximately 90 apart. The key ribs 12512 are of such length that when the key is fully inserted into the key socket 127, the outer ends of the key ribs 1255 are above the ward opening 12S so that the key can be revolved to turn the latch lili). The relationship is such that the angularly spaced grooves 1271) in the key socket 127 only line up with the angularly spaced grooves 12821 in the ward opening 123 when the latch 156 occupies its latching position, with the latch nose 160e projecting rearwardly into a position which` is eliecting latching engagement with the stop lobes 91, 92, 93, or is capable of effecting latching engagement therewith. Conversely, after the key 125 has been inserted through the ward opening 12.8 into the key socket 127, and has been turned to revolve the latch into releasing position, the keycannot be withdrawn because the angularly spaced lugs 12515 projecting from the shank of the key have been revolved out of registry with the angularly spaced grooves 1285 in the ward opening 128. In this latch releasing position of the key 125, the slide panel 49 can be pulled down into the second stage of its signalling operation; and it can also be restored back to its normal position, or can be removed entirely from the cover plate 35, as for replacing the fracturable insert 85. The key operated rotation of the latch le@ into such releasing position has twisted the lower end of the torsion spring 120 still further in a counterclockwise direction (FIGURE 4) so that this spring now exerts additional counter-torque tending to revolve the latch back into its latching position.

Referring more particularly to the stationary stop cam lobes 91, 92, 93 and the stationary latching recesses 94, 95, 96 at the ends of the lobes, all formed integral with the stationary cover plate 35, it will be seen from FIG- URES 9 and 10 that the uppermost lobe 91 has a rising cam slope 91a leading up to a right angle-drop-off shoulder 9111 at the trailing or lower end of the lobe 91. This right angle shoulder 9111 defines the top of the lirst latchng recess 94, into which the latching nose 109e swings when the slide panel lil is moved into the normal position shown in FIGURE 6, in which position the two electrical switches 44, 44' are in their normal non-signalling positions. The second cam lobs 92 has a rising cam slope 92a leading upwardly from the lower end of the first latching recess 94, the beginning or loading end of this rising cam slope 92a starting in a small recess or depression 97 formed in the face of the cover plate 35, so as to avoid any slight casting spur or irregularity in the cam slope 92a, which might affect the desired smooth upward movement of the latch nose ltltlc along this cam slope 92a. The trailing end of this second cam lobe 92 also has a right angle drop-olf shoulder 92's defining the top of the second latching recess 95. The rising cam slope 92a of the lobe 92 is operative to cam the latching nose 109e outwardly out of the first latching recess 9d when a substantially predetermined amount of pull-down force is manually exerted on the slide panel 4i) through the linger pocket 1M, for Inanually operating the box into its iirst stage of signalling operation, resulting in the upper electrical switch 44 being moved into its signalling position (FGURE 7). It is during this stage of pull-down motion of the slide panel that the fracturable insert 85 is broken. Intermediate the crest of the rising cam slope 92a and the drop-off shoulder 921;, the lobe 92 is formed with a dwell surface 92C having a slight reverse or regressive angle of slope.

The third stop lobe 93 is formed at the base end of the latching recess 95 with a right angle stop shoulder 93a extending outwardly or forwardly to a substantial height above the bottom of the latching recess 95. This third stop lobe 93 is also formed at its lower end with a right angle drop-oli shoulder 9311 defining the top of the third latching recess 96, the bottom of this latching recess being defined by the top flange 88 of the socket 84 for receiving the fracturable insert. The forward ridge or surface of the stop lobe 93 is formed with a iiat dwell area 93e followed by a rearwardly inclined slope 93d. It will be noted that the upper stop shoulder 93a of the stop lobe Q3 projects forwardly substantially beyond the dropoff shoulder 92% and dwell surface 92C of the second lobe 92, whereby in the first stage of pulling down the slide panel lil the latching nose 106e will be sure to strike the upper stop shoulder 93a of the third lobe 93, and thereby positively prevent the manual pull-down operation from accidentally carrying the slide panel down through its first stage position and into its second stage position (FIGURE 8). To increase the areas of surface contact between the underside of the rotating latch nose liltlc and each of the dwell areas 92e and 93C, these latter dwell areas are each chamfered off along one side to form a sloping bearing surface lil?. (FlG- URE 13), so as to increase the extent of surface contact betwen such lobe `areas and the underside of the latch nose 169e. The angle of the sloping bearing surface 192 is shown at the crest of the lobe 92 in FIGURE 10,

and the angle of this bearing surface 1112 decreases in both directions from the crest to maintain iiat surface contact between such fiat inclined bearing surface 162 and the fiat under surface of the latch nose 10de as this latch nose ltltlc swings rearwardly in a direction towards the bottoms of the notches 9d, 95, and 96.

Referring brieiiy to the electrical connections of the signal station, it will be seen from FlGURES 14 and 15 that the lower electrical switch 44 controls circuit Y comprising conductors Y-Y"; and that the upper electrical switch controls circuit X comprising conductors X'-X. If desired, two of the conductors, such as X and Y can be combined into a common conductor, so that the two circuits X and Y can be maintained over three conductors. As previously described, these circuits can be of the normally open type, in which current does not flow until either or both of the switches 44, 44' are closed in the performance of a signalling operation; or they can be of the normally closed type in which current continuously ilows through both circuits until either or both of the switches 44, 44 are opened in the performance of a signalling operation. In some instances, the signal station may have one of the electrical switches and one of the control circuits omitted, these generally being the lower switch 44' and its control circuit Y.

in FlGURES 17, 18 and 19, l have illustrated a slightly modified embodiment characterized by the use of a locking ring or washer which establishes a locking relation between the electrical switches 44, 44 and the mounting thereof on the back of the stationary cover plate 3S, one of these locking rings being provided for each switch. These locking rings 135 are used primarily in this modified embodiment in which the mounting clip 51 and the terminal block 'lil are omitted from the assembly. Such locking rings 135 serve to compel the assembly of each electrical switch with the housing thereof disposed in a horizontal plane so that the toggle operating lever 45, 45 thereof is movable horizontally in response to the action of the deiiecting wings 111, 1F12, these locking rings also serving to positively loci: each switch permanently in this horizontally disposed postion against any stresses, vibrations, etc. The locking ring comprises an inwardly projecting locking lug 136 which is adapted to have an axial sliding fit in a keyway 137 formed along one side of the externally threaded switch stem d8, thereby locking the switch assembly to the locking ring in a fixed angular relation. The locking ring also comprises an outwardly projecting arm 13S having a laterally bent key 139 at its end, which key is adapted to lit into either one of two locking slots 149, 14d which are punched out in the depressions .57 formed in the cover plate on diametrically opposite sides of the stem receiving holes 55. The engagement of the key 139 in either of these locking slots insures that the switch has to be mounted on the backside of the cover plate 35 in a horizontally disposed position. The provision of the two slots Mtl, 140 enables different designs of switches to be installed, such as those in which the righthand position of the switch operating lever 45 establishes the closed circuit position, and those in which the lefthand positon of the operating lever establishes the open circuit position, which is contrary to the operating relation above described. Still further, the provision of the two slots 14d, 140 enables the electrical switches to be reversed, as for converting the signal station from a normally open circuit type of station into a normally closed circuit type of station, as referred to above. The provision of such locking ring 135 is also advantageous in that when the switch mounting clip 51 and terminal block 70 are dispensed with, the locking rings 135 will still hold the electrical switches in their horiozntally disposed positions. The use of such locking rings 135 also is advantageous in situations in which it may be desired to omit one of the electrical switches. in either of the above situations, the rear conduit box Ztl may also be dispensed with.

Referring briefly to the operation of my improved signal station, it will be seen from FIGURES 1, 2 and 6 that in the normal condition of the signal station, the front slide panel 40 occupies an upper position, with both toggle operating levers 45, 45 thrown into the left-hand positions shown in FIGURE 6.

When an employee, passer-by, watchman, etc., desires to have the signalling station transmit a signal, he inserts his fingers into the linger pocket or recess 104 in the upper portion of the slide panel 40, and pulls downwardly on the panel. To effect downward sliding movement of the panel in the performance of this initial signalling operation, it is necessary that this downward pull be sutiiciently powerful to revolve the latch nose 100C outwardly (against the opposing torsional twist of the torson spring 120) suiiiciently to enable the latch nose to ride upwardly on the leading cam slope 91a of the first cam lug 91. The resistance of the torsional twist of the torsion spring, and the rotative frictional resistance of the rotatable latch 1G@ to being rotated, establish suicient resistance so that ordinarily the slide panel 46 cannot be pulled downwardly by any mischievious child or young prankster. It will be seen from the foregoing that the torsional twist of the spring 120 plus the frictional resistance of the latch 100 against turning, are ample to hold the slide front 40 in its normal elevated position (FIG. 6), irrespective of whether the fracturable insert S15 is or is not employed. When the insert is employed, additional downward pull must be exerted on the slide front 4t) to fracture the insert. With the slide front 44) in its normal elevated position there is a substantial vertical space between the bottom edge of the fracturing ram gti and the insert Sli (shown in FIG- URE 6), so that the slide front can have substantial momentum for breaking the insert when pulled down sharply. If pulled down slowly, considerably more force must be exerted on the slide front to fracture the insert.

As the slide panel 4t) moves downwardly toward its first signalling position, the deflecting wing lll starts defiecting the over-center snap lever 45 of the first electric switch 44 in a direction toward the left. When the slide panel completes this first stage of its pull-down movement, into the position shown in FIGURE 7, the switch lever 45 has also completed its snap movement to the left for actuating the contacts of the switch 44 into signalling position, thereby resulting in the transmission of the first signalling impulse over circuit X. The pull-down motion of the slide is automatically stopped in this first stage of signalling operation by the action of the latch nose 100e snapping down oit the first cam lug 91 into the positive locking recess 95,

It the local situation which prompted the initial pulldown of the slide panel continues, or should grow worse, a supervisor or other person of authority-goes immediately to that particular signal box and inserts his key 25 into the latch i) and rotates the latch to clear' the third cam lug 93. Thereupon, the slide can be pulled downwardly into the next stage of its signalling operation, shown in FIGURE 8. The start of this second stage of downward movement brings the deflecting wing 111', against the operating lever 45' of the second switch 44', so that in the continuation of this second stage of pulldown motion, the lever 45 is swung into the left-hand position shown in FIGURE 8, which thereupon actuates the contacts of the switch 44 into signalling position to cause the transmission of a second signalling impulse over the second signalling circuit Y. The pull-down movement into this second position (FIGURE 8) can be performed by the pull-down force of the tingers inserted into the finger pocket lil-3, or it can be effected by pulling down on the key $.25, which is prevented from pulling down out of the latch by reason of the fact that it is then holding the latch rotated into its releasing position. The pull-down torce required to move the slide down into this second signalling position is substantially less than the force required to move the slide into the first signalling position, by reason of the fact that at this time there is no fracturable insert to be broken, and the latch nose e does not have to be cammed up a leading cam slope such as slope 91a. At the completion of this second pull-down movement, the latch nose 16h05 drops oli the trailing edge of the third lobe 93, into the locking recess 96. The two signalling operations ot the signal station have now been completed.

Referring now to the restoration of the slide panel back to its normal position (FIGURE 6), this can only be elifected when the key is in place in the lower end of the latch it), and is rotatably holding the latch ltl rotated into its releasing position with the latch nose 100C projecting outwardly in such position that it will clear all of the trailing right angle stop shoulders 93b, 92h and 91h. In the restoration operation, the slide panel 40 is pushed upwardly slightly beyond the normal position shown in FIGURE 6, so as to expose the mounting socket 84 below the lower edge of the panel in position to receive a new fracturable insert 8S, whereupon the slide panel can then be moved down into its normal position. It will be noted that the inclined cam slot llt), together with its two dellecting wings lll and lll', function to automatically restore the two switches 44 and 44 back to normal positions when the slide panel is returned to normal position, so that no separate manipulation of these two switches is required.

Attention is directed to the fact that the two switches 44, 44 cannot be surreptiously moved by any unauthorized person into either their normal postions or their actuated positions through vibration, pounding, etc., owing to the positive confining action of the rib barriers 90, 111, lll and 115.

The slide panel t9 can be removed entirely from the stationary rear cover plate 35 by holding the latch bolt Ill@ rotated into its releasing position, and sliding the slide panel 4t), upwardly until the side guide grooves 83 therein move out of registry with the guide lugs 82 on the rear cover plate 35. This removal of the slide panel gives access to the switches 44, 44', to the mounting of the cover plate 35 on the box housing 20, and to other parts of the internal construction. lf at this time, one or both of the switches 44, 44 should be accidentally moved into their actuated position, the provision of the previously described blocking offset 90 (FIGURES 6 8) operates during the reassembly of the slide panel on the box to positively prevent the slide panel 4t) from being slid down into its normal position. It will be seen from FIG- URES 7 and 8 that this blocking offset 90 is so aligned that it will strike the ball end 45 or 45 of any switch lever then in its actuated position, and can only be cleared to permit continued downward movement of the slide panel into its normal position by moving the lever of such switch over into its normal position. This prevents faulty assembly or reassembly of the construction.

With regard to the optional characteristic of the fracturable insert 85, it will be seen that the present signalling station will operate with or without it. The torsional twist of the spring l2@ and the frictional resistance of the latch ldd will hold the slide panel in its raised normal position (FIG. 6), irrespective of the presence or'absence of the fracturable insert in the socket 84. However, at the present time it is desirable to make provision for the use of the insert because some states require it, while other states do not want the insert furnished. Also, the fact that the signalling station can only be operated by first breaking something, either a glass or fiber bar, etc., is often a deterrent to tampering because many persons believe that unauthorized breakage will result in an alarm and immediate arrest. Also, from a pyschological standpoint, some persons feel that the seriousness of a fire or emergency alarm Warrants or requires the breakage of some part of the signalling station.

While l have illustrated and described what I regard to be the preferred embodiment of the invention, nevertheless it will be understood that such is merely exemplary, and that numerous modifications and rearrangements may be made therein without departing from the essence of the invention.

l claim:

1. In an emergency call box, the combination of (a) a mounting support,

(b) a manually engaged pull-down slide panel,

(c) means mounting said slide panel on said support for vertical rectilinear sliding movement from a normal position into a plurality of signalling positions,

(d) a plurality of electrical switches responsive to the movement of said slide panel into said plurality of signalling positions,

(e) manually engaged means for manually sliding said slide panel downwardly from one of said positions to another,

(f) and latch means controlling the sliding movement of said slide panel from one of said signalling positions into another of said signalling positions.

2. In a signal station, the combination of (a) a mounting support,

(b) a slide panel,

(c) means mounting said slide panel on said support for sliding movement from a normal position into a plurality of successive signalling positions,

(d) a plurality of electrical switches successively responsive to the movement of said slide panel into said successive signalling positions,

(e) manual actuating means for manually sliding said slide panel from said normal position into one of said signalling positions,

(f) and key-controlled latch means controlling the sliding movement of said slide panel from one of said signalling positions into another of said signalling positions.

3. The combination of claim 2 wherein said key-controlled latch means is mounted on said slide to have sliding movement therewith.

4. The combination of claim 2 wherein said key-controlled latch means is in the form of a rotatable element mounted on said slide with its axis of rotation extending substantially parallel to the line of sliding motion of said slide.

5. In a call box for transmitting emergency signals, the combination of (a) a mounting support,

(b) a manually engaged pull-down slide,

(c) guide means mounting said slide on said support for substantially vertical rectilinear sliding movement thereon from a normal position into first and second switch actuating positions,

(d) first and second electrical switch means arranged to be actuated when said slide moves into said first and second switch actuating positions,

(e) stop lug means carried by said mounting support,

(f) la key released rotatable locking bolt carried by said slide for cooperating with said stop lug means to control the movement of said slide from one of said switch actuating positions to another, and means mounting said locking bolt -on the back side of said slide for rotational motion about a substantially vertical axis.

6. In a signal station, the combination of (a) a relatively stationary support member,

(b) a manually actuated pull-down slide member,

(c) cooperating guides carried by said members operative to mount said slide member for substantially rectilinear pull-down sliding movement on said support member between a normal position and iirst and second successive switch actuating positions,

(d) iirst and second electrical switch means arranged to be actuated by said slide member when it moves into said first and second switch actuating positions respectively,

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(e) stop lug means carried by said relatively stationary support member,

(f) latching means carried by said pull-down slide member and adapted to cooperate with said stop lug means for normally preventing said slide member moving from said iirst position into said second position, and key means for releasing said latching means t-o permit movement of said slide into said second position.

7. The combination as set forth in claim 6, wherein one of said members is provided with means for mounting a fracturable insert, and wherein the other of said members is provided with breakage means for fracturing said insert when said slide member is moved relatively to said support member in the performance of a signalling operation.

8. In a signal station, the combination of (a) a mounting support,

(b) electrical switch means carried by said mounting support,

(c) a plurality of electr-ical circuits adapted `to be successively controlled by said electrical switch means,

(d) a slide panel mounted on said mounting support for sliding movement from a normal position into a plurality of signalling positions, whereby to eir'ect successive operation of said electrical switch means for successively controlling said plurality of electrical circuits,

(e) and key released latch means controlling the sliding movement of said slide panel from one of said signalling positions into another of said signalling positions.

9. In a signal station, the combination of (a) a mounting housing,

(b) a slide panel carried thereby,

(c) guide means carried by said housing and by said panel for permitting said slide panel to have vertical sliding movement on the face of said housing,

(d) switch mechanism carried by said housing,

(e) switch operating means extending from said switch mechanism and operative by substantially horizontal movement from side to side to operate said switch mechanism,

(f) and deiecting means carried by said slide panel and operative in the vertical sliding movement of said pane-l to impart horizontal movement to said switch operating means.

10. In a signal station, the combination of (a) a mounting housing,

(b) vertically extending guide supports carried by said mounting housing,

(c) a front slide panel covering substantially the entire front of said housing,

(al) vertical guide ways carried by said slide panel and cooperating with said guide supports for permitting vertical sliding movement of said panel into different positions extending above and below said mounting housing,

(e) a pull-down recess in said front slide panel adapted to accommodate the fingers of an operator when he desires to pull the slide panel downwardly in a signalling operation,

(f) electrical switch mechanism mounted in said hous- (g) switch operating lever means extending from said switch mechanism and operative by substantially horizontal movement from side to side to operate said electrical switch mechanism,

(h) deliecting cam means on the back side of said front slide panel and operative in the vertical sliding movement of said panel to impart horizontal operating movement to said lever means, i

(i) a plurality of stop lugs projecting from said mounting housing means,

l(j) and key releasable latch mechanism carried by said weasel 13 slide panel to move vertically therewith and comprising a latching nose adapted to cooperate with said stop lugs.

11, The combination of the subject matter set forth in claim 10 wherein said mounting housing is provided with a supporting pocket for receiving and supporting ythe ends of a substantially horizontally extending fracturable insert, and wherein said slide panel is provided with Aa fracturing wedge adapted to engage the central portion of said insert for breaking it in ltwo when the slide panel is pulled downwardly. v

12. The combination as set forth in claim 10 wherein one of said stop lugs has a rising cam slope along its leading edge up which the latching nose must travel in the initial pull-down motion of said front slide panel.

References Cited by the Examiner UNITED STATES PATENTS 942,433 12/09 Bretney 340-305 1,219,230 3/17 Blackmore -1 20G-18 1,522,911 1/25 Robinson ZOO-18 2,857,040 5/32 Bulen 200--168 1,885,147 11/32 Smith 200--18 1,890,375 12/32 Garret 1 200-18 2,067,705 1/37 Corbett 340--297 2,148,913 2/39 Stevens 20G-153.12 2,170,154 8/39 Moore 200-17 2,726,381 12/55 Verkuil 340-303 2,789,167 4/57 Erbstosser 20G-153.12 2,821,580 1/58 Black 200--17 2,868,906 1/ 59 Soreng 200--44 2,985,741 5/63 Ellrnan 20G-168 3,097,347 7/ 63 Simjian 20D-44 3,116,479 12/ 63 Kingsmore 200-18 X NEIL C. READ, Primary Examiner. 

1. IN AN EMERGENCY CALL BOX, THE COMBINATION OF (A) A MOUNTING SUPPORT, (B) A MANUALLY ENGAGED PULL-DOWN SLIDE PANEL, (C) MEANS MOUNTING SAID SLIDE PANEL ON SAID SUPPORT FOR VERTICAL RECTILINEAR SLIDING MOVEMENT FROM A NORMAL POSITION INTO A PLURALITY OF SIGNALLING POSITIONS, (D) A PLURALITY OF ELECTRICAL SWITCHES RESPONSIVE TO THE MOVEMENT OF SAID PANEL INTO SAID PLURALITY OF SIGNALLING POSITIONS, (E) MANUALLY ENGAGED MEANS FOR MANUALLY SLIDING SAID SLIDE PANEL DOWNWARDLY FROM ONE OF SAID POSITIONS TO ANOTHER, (F) AND LATCH MEANS CONTROLLING THE SLIDING MOVEMENT OF SAID SLIDE PANEL FROM ONE OF SAID SIGNALLING POSITIONS INTO ANOTHER OF SAID SIGNALLING POSITIONS. 